Diamonds in Arkansas
THE ONLY PLACE in the World where anyone can come, pay a small fee per day, and hunt on a documented authentic diamond-bearing pipe is located just 2.5 miles south southeast of Murfreesboro in Pike County. Diamonds were discovered here in 1906 by a local farmer-prospector. The pipe was mined from 1910 through 1929 and was a private tourist attraction from the 1950s to 1972, when it was sold to the state and converted into a state park. It has been estimated that over 100,000 diamonds have been recovered from the 35 acre plowed field. This site holds the record for the two largest diamonds found in North America - the Uncle Sam (40.23 carats rough) and the Star of Murfreesboro (34.25 carats rough ). Since it became a state park in 1972 over
20,000 stones have been recovered by tourists and local diggers.
How do you hunt for a diamond? First of all, you have to know what you are looking for! The park has a display of diamonds and a slide show so that you can learn more about what a rough diamond crystal looks like. Take the time to see the show and look at the exhibits before you run out onto the field. There are several techniques for hunting a diamond, the method you choose will best be determined by how much time you have to spend. Keep in mind, you are looking for something very small, on the order of the size of a paper match head to as large as a green pea. Dirt does not stick to diamond, making a sunny day after a heavy rain an ideal time to go diamond hunting.
If you expect to find a brilliant-cut faceted diamond, the only way that will happen is if you find the stone that fell out of somebody's ring (it did happen). Natural diamond crystals are clear, may or may not be colored, and have a special luster, and don't look at all like what you see in a jewelry store. By the way, if you stop in a rock shop advertising "Hot Springs Diamonds", those are faceted quartz crystals, not real diamonds. They are pretty, but not real diamonds.
If you have a few hours: Two different methods are used. One I call "slow-walker". With the sun over your shoulder, walk slowly up and back each plowed furrow, looking on the well-lit side and top of the mound. Check every sparkly item, realizing that most of what you will see are tiny flakes of a golden mica (phlogopite). Or broken pop bottles, ect. If your eyes are good, then how much ground you cover helps determine your chance of finding a diamond. The second method is one of sitting in one spot (spot-sitter) and carefully examining everything in a given area. You might take a window screen frame (without the screen and painted flat black) and lay this on the ground. Look at everything inside the frame, then move the frame, and look again. Don't overlap where you have already looked. This method's success is due to the fact that you are looking at everything in a small area in much greater detail than the slow-walker. The slow-walker will find stones that average larger size, whereas the spot-sitter will find more, but smaller stones, on average.
If you have a day: You can combine the two methods above so you don't get bored. Or you may wish to rent some screens from the park supply and screen and wash material. This method requires that you get your hands in water, which, during the winter months, may be too much for even veteran collectors to tolerate. You need a small scratching tool, like a three-tined garden weeder to scratch up the soil to wash. Stay away from large rocks and gravels, but instead scratch them aside to get at the smaller material filling in between the cobbles at the bottom of the plowed furrows. Look for places where small deltas have formed by running water at the lower ends of the furrow and work through the material at the upper end of each delta.
Using screens and pans
You may wish to rent a seruca from the park. A seruca is a special type of screen which is similar to a gold pan, but has stainless steel window-screen wire in the bottom, and is round bottomed. After screening out the over-sized material and looking for diamonds in it, you place about a cup of washed fines that hold on a window screen in the seruca. Working it partially submerged in water with a gold pan type action will result in all the heavy minerals being concentrated on the screen bottom. Then you take the seruca from the water, gently tap on the side a couple of times to cause the excess water to drain, then deftly flip the pan upside down onto a cleaned off level spot. If done correctly, the heavy minerals, including diamond, are positioned on top. Let dry and carefully examine, using a pocket knife blade or small trowel to extract any diamonds. You may wish to simply take a trowel and cut under the heavies, placing them in a small bucket to take home or to your campsite to look at later when you have more time.
If you have more than one day: Buy your own seruca from the park's gift shop. Before your trip, build some small (2'x2') sorting screens, one with 1/2 inch, one with 1/4 inch, and one with window-screen size holes.Before you start with the screens and seruca, meet and talk to the park rangers and local diggers at the Crater. They can give you many more tips and hints.
Want to read about the park and its geology and history? Get the following references:
Finding Arkansas Diamonds by J. M. Howard, a free pamphlet available from the Arkansas Geological Survey, address listed elsewhere on this web site.
Kidwell, A. L., 1990, Famous mineral localities - Murfreesboro, Arkansas: Mineralogical Record, v. 21, p. 545-555. A good historical perspective with some geology thrown in on the Prairie Creek pipe and park.
Reneau, Randall, 1993, Crater of Diamonds: Rock & Gem Magazine, June, p. 14-16. pipe (Crater of Diamonds State Park) in Pike County.
Selbert, Pamela, 1992, Combing the Crater: Lapidary Journal, Nov., p. 53-54, 84-92.
See also Famous Locations, Crater of Diamonds